A little messy but it was just a test...Using a 1kOhm resistor and NTC in a voltage divider on analogport 5. Seems to be working quite nicely.The inverting of Vout was done because I was too lazy to flip my voltage divider around.

The equations were taken from wiki and the numbers (B value) were just googled, so no warranty on them being correct.

I'm working on something like this and I'm trying to calculate the B value. With a 1k resistor and an NTC probe that has a different B than your sample here, I'm getting a reading on my analog input of 1014 at 0 degrees C and 649 at 100 (i put the probe in ice and boiling water) - that's the raw value, not inverted.

How do I take that 1014 and 649 reading and convert that the resistence so I can plug it into b = Ln(R t1/ Rt2) / (1/T1 - 1/T2) ?

It will teach you about the equations, coefficients, and has some code to calculate the coefficients. I did this with my 2 salvaged thermistors and it works very well so long as I use the full Steinhart-Hart equation.

You can also have a look at the library I added to the playground:http://www.arduino.cc/playground/ComponentLib/Thermistor4

I have a lot of documentation in the source that will probably answer most questions.